As is well known, a laser lamp is mainly composed of three parts including a laser light source, a mechanical movement mechanism and a diffractive optical element, wherein micro/nano-scale microstructures are processed on the surface of the diffractive optical element. The diffractive optical element can be used for outputting incident dot laser as a required image by utilizing a diffractive effect of the micro/nano-scale structures on light. Due to the characteristics of high brightness and high collimation of the laser, the laser lamp can achieve long-distance and high-brightness image display, thereby having been rapidly developed on European and American markets and the domestic market in recent years.
Although laser lamps have been used for over 10 years, at present, most of laser lamp products on the market can only display static images. In order to enrich the representation content and improve the representation effect, the laser lamp is required to achieve dynamic display of an image, namely arbitrary image transformation, image translation and image rotation. The problem urgent to be solved in the industry is to achieve an ideal dynamic display effect of the laser lamp serving as a mass consumer product on the premise that the cost and the system complexity are not increased obviously. In order to achieve a good dynamic image display effect, overall optimization is required on the aspects of the optical design of the diffractive optical element, an arrangement way of each frame of images and a mechanical movement structure. At present, static images or combinations of static images without internal relations thereamong serve as mainstream laser lamp products, and a small number of products can achieve certain dynamic image display, however, the effect is unideal.
The existing solution for achieving a dynamic effect on the laser lamp mainly includes: each frame of patterns is arranged in a sector to form a ring, and the whole ring-shaped diffractive optical element do circumferential movement around the center of a circle. The solution has the advantages of simple and reliable structure and low cost, however, each frame of images can rotate around a rotation center in a display process to result in image swing to affect the display effect.
In order to achieve the dynamic image display of the laser lamp, it is required to take the three factors into comprehensive consideration: (1) the design for the optical structure of the diffractive optical element: in order to achieve dynamic display of images, a certain amount of microstructures are required to be made on the surface of the same diffractive optical element, and each of the different microstructures corresponds to a frame of images. In order to achieve translation and rotation effects of the images, design means such as central symmetry and off-axis are required to be comprehensively used on the optical design aspect of the diffractive optical element; (2) the design for geometric parameters of the diffractive optical element: in order to achieve the dynamic display of the images, a series of microstructures are required to be made on the surface of the diffractive optical element, and geometric parameters such as size of single microstructure, the relative position of the adjacent microstructure and the arrangement way of the microstructures directly affect the dynamic image display effect. The parameters are required to be determined by taking the response characteristic of human eyes or a detector and the movement characteristic of a mechanical movement structure of a diffractive optical device into comprehensive consideration; and (3) the design for the mechanical movement structure of the diffractive optical device: a relative translational movement is required between a laser beam and the diffractive optical device in order to achieve the dynamic display of the images. The smooth transition among different frames of images can be achieved only by matching the movement with the geometric design parameters of the diffractive optical device.
The information disclosed in the background is merely intended to strengthen the understanding of the overall background of the present invention, but should not be regarded as an admission or any-form suggestion that the information constitutes the prior art well known by the ordinary skilled in the art.